Demagnetizer



April 24, 1928.

1,667,422 J. A. LEWELLYN DEMAGNETI ZER Filed Nov. 13. 1920 Patented Apr. 24, 1928.

LGGYAZZ UNITED STATES PATENT OFFCE.

JOHN A. LEWELLYN, OF TOLEDO, OHIO, assitance., er Mnsnn assrsnnnnrs, To ROB- nn'r n. HrNns, or TOLEDO, OHIO.

DEMAGNETIZER.

Application filed November 13, 1920. Serial No. 423,83

This invention relates to apparatus for treating magnetizable material and articles for removing magnetic charge therefrom.

This invention has utility when incorporated in electromagnet demagnctizers, especially ot the alternating current type, adapted to disperse magnetic conditions from tools and Work, especially as arising from the use of magnetic chucks.

Referring to the drawings:

Fig. 1 is a perspective view ot an embodiment of the invention as a Work-bench tool or apparatus of alternating current type oi electromagnet demagnetizer;

Fig. 2 is a longitudinal section through the apparatus of Fig. l;

Fig. 3 is a plan view ot the apparatus ot Fig. 1, with parts broken away; and

Fig. a is a wiring diagram.

Laminations 1, of soilt steel or iron, selected of a character to readily give up niagnetism and preterably with a lou7 hysteresis loss, to reduce heating, are assembled beh tween plates 2 and held by bolts 3. These assembled laminations form a core providing an intermediate majo-r pole portion et, and one on each side thereof, terminal pole portions 5. These terminal poles 5 taken together approximate in capacity the capacity ot the intermediate pole 4t.

From a source or' current supply, as alternating current generator 6, lines 7, 8, may extend past switch 9 as an insulated covered cord 1() entering through opening 11 general housing or non-magnetic box 12, in which the core L1, 5, may be anchored by composition 13 ol' insulation material, which material may also envelop coil lll in said housing 1Q. This coil 1e is shown as disposed about the intermediate or major pole l, thereby energizing the major pole and simultaneously oppositely energizing the terminal poles 5. As the terminal poles 5 thus have the same polarity, there is a ilus: simultaneously in opposite directions trom the pole a.

In practice, the current supply may be 110 volt alternating current, sixty cycle, with the coil 14 of sufficient resistance properly to take care oi such. As thus designed, it is readily connected by usual socket and plug to the normal lighting circuit. The demagnetizer so energized would have magnetic Hui; reversals responding to the current cycles, but each simultaneously in opposite directions iro-m' the major or intermediate pole el, thereby promoting the establishment in the article to be treated ot a built up magnetism as the article is moved inward from one end tor thereby quenching any Vopposing magnetism, and then gradually working such magnetism doivn by moving the article ofi the opposite end or' this device.

ein armature 15 is sealed by the composition 13 as a closure or cover Vtor the housing 12, rendering the structure as a Whole moistureprooi. This armature on its inner face is in contact with the several poles 4, 5. 'lhe magnetic flux chan due to the cycle frequency involves subjec ng an article to be magnetized to m ny magnetic changes in passing across the arnuiture 15 lengthwise 'from a terminal pole across intermediate pole et and then past the remote terminal pole Further breaking up ot the magnetic fluxes in this region oit magnetic inliuencev is had by interrupting vthe continuity of the extent of the magnetic material in the general line of movement ol the article across the armature 15. To this end, the armature 15 is Oi grid ormwith bar portions 16 parallel to each other extending transversely of the path across the three poles et, 5 which serve to break up the held. ln order that the armature may serve as a cover for the demagnetizer, as well as provide a` platform over which the article to be treated may be. conveniently slid or moved. interposed between the bars 16 is r non-magnetic metal 17. These bars, in the normal energizing ot the electro-magnet ot this demagnetizer, develop polarities, with the intermediate weakened or nearly neutral regions. Accordingly in passingv a drill, or some machine part which has a magnetic charge, even rapidly across the armature plati'orin 16, 1T, in a ino-vement across the poles 5, it, 5, there are encountered not only `the many neutral intervals between the reversals ot polarity and reversals of magnetic ilus due to tne alternatingcurrent, but there is additional magnetic influence disturbances due to the loiver magnetic action at the non-magnetic regions 17 of the grid armature. ln practice this insures such a weakened magnetic strain at the removal point ol' the article treated, that residual magnetism therein is negligible, it not practically all eliminated. One passing of the say both positive as the-pole2l ienegative, then. With thereversa-l of. the current, 'the pole 4: is positive and the. poles 5 are negative. Inasinucliyasthisis alternating cu`rrent, thesegtluctuations ai'e'fot sign charac-V ;teristio .and :recur very. rapidly V.thereby l tivecn the pair ot' the poles oi croi'fdiug` through the ii nos inthe armature l5 which fluxes between the poles are interruptedby themen-magnetic :regions i7 An -article which isto be demagnctized may .be

placedupon this energized devicevsaycat the lett or cordend iii Fig. land gradually moved to the right lor. upper portion `across this ydevice in contactl ivitlithe arii'iature l5. The flux cycles yot magnetism arein inani- H'iuiu lasthe device. is `in .direct circuit be- Vitmay be of an extent to be-iin tlietivo circuits between the outerpoles and the inner pole. Gradual shifting o't'lthe article longitudinally ot the -devicebringsabout the, fluxA leakage from .the armature into the A,article Witlrsuch iux .lealrae asolus 'and thenininus as. the iuxes to l.

.reverse,;tlie pealr -.ofsiicli fluxes being ofa diminishing. iiaturel-astlie articleis gradually shittedoislid crear ot the armature l5. ylit/'lint'. is claimed and it is desired to secure by Letters Pateiit, is: fl. The-method ot deiiiagnetizing annabnetically cli-urged :article Ycomprisingl exposing theV article .to decreasing cycles of..v inag- .netic tina-.by placingsaid article in Contact With magnetic .poles carryingr said Y,iiix and simultaneous-lv nf.. similar polarity and shitting the .article trom a position thereon transverselyof theiparallel extent otcsaid poles 'to' clear position away from saidv poles 2. The Amethod .otdeiiiaguetizing a .niagnet'cally 'charged article comprising generportion, a coil-for at@ pole. @iv-iiOSltely .front and a ldemagnetizing- `ai .ating Zone ofinaxinium flux reyersing cycles, mergingot' said cycles to provide a .neutral.regionand-aiisiiia the. m-

c le to move .from the maximum zone to and out of said neutral region, said article during said movement being in contact With magnetic poles carrying said ilux and simultaneously of similar polarity.

3. A. deinagnetizer including a section o ,influence including flux carryingpoles; to be contacted by the article tonbe demagiietized, an electroiigiagiiet for maint iig/said sec- .tionr oic influenceY zsaid yelec oiiiao'iiet. `em- -7 y i. C! i :bodying Y simultaneouslyv simil jiie'li'ity terminal poles, a. housing Vtor' sustan ing' the .magnetic iniiueiice sectionand enclosingtlie elfectioiiiagnet,`Y and. fa nonfconductor iioiimagnetic lillerhtor the housing. i W

4l. An alternatingV currentuelec-troinagnet deniagnetizer provided with tivo.similar fpolarity.regions and anarinature;,having parallol. nonfinagnetic strips transversely of said region. l I EL; J

An alternating4 current A`electroniagiiet provided with a laminated core liapvinga vmajor intermediate pole asarogioiioi inagnetic {iu/X, and a pair; orfterminal pole4 portions together zipproiiiinatnig tliestrength of magnetic flux the in eiineiliatc pole ininal poles.

:latiirewacijoss said ,poles provided Withwa non-magnetic. VVgap uniformly Yspaced from a pairot pole pory 46.I A de agnetizen comprising `a Uthreepole electromagnet cor-e, alternating. ,cur

rentcoil simultaneously similarlyleiief'giifzing; the first and third poles` otisaidcore, an armature across `said poleszt non-magnetic `means set into;` said armature. uniformly transversely of the ldirect flux between. the

polesto break up the regions oflinagnetic intensity` and a iion-inaf `iietic inountinvzioru H i. D i D.

the armature housingl ythe core and magnet. coilMw v .i

In Witness whereof I atix my signature.

JOHN ii. LiiivnLtYii. 

